Delusions and delusional reasoning.

In 2 studies, delusional participants assigned higher probabilities to narratives of actual delusions than participants with no history of delusions; previously delusional participants did not differ significantly from delusional participants or participants with no history of delusions. In Study 2, the authors found that this reasoning bias was specific to delusions and did not generalize to "neutral" text. Familiarity with the content of the delusion narratives played a mediating role in the estimation of their probability, but delusional status also had a significant, independent effect. These findings are consistent with the Bayesian model of delusion formation proposed by D. R. Hemsley and P. A. Garety (1986), and with R. P. Bentall, P. Kinderman, and S. Kaney's (1994) concept of "emotional saliency." A productive area of future research might be to further determine the elements of "emotional saliency" and their impact on the individual steps of the Bayesian model.

Head injury and alexithymia: implications for family practice care.

BACKGROUND: Alexithymia, a deficit in emotional information processing, and a history of head injury have both been found to be related to high rates of psychosomatic illness, substance abuse, depression, and utilization of primary care services. To date, no study has examined the potential comorbidity of alexithymia and head injury in a family practice setting, a necessary step in evaluating the aetiologic role of head injury in the development of alexithymia. The goals of this study are to establish prevalence of head injury and alexithymia in a family practice setting and to evaluate the relation, if present, between the two. METHODS: Patients (n =135) of a family practice residency facility were screened using the Traumatic Brain Injury Questionnaire and the Toronto Alexithymia Scale-20. RESULTS: Forty-nine per cent of the participants reported a history of head injury and 18% were alexithymic. Those with a history of head injury had significantly higher scores of alexithymia. Chi-square analysis indicated a relation between head injury and alexithymia. CONCLUSIONS: The high rates of self-reported history of head injury in family practice settings, particularly in the context of alexithymia, may adversely affect a physician's ability to care for these patients. Increasing physicians' awareness of head injury and the potential mediating role of alexithymia in medical and psychological illness may facilitate effective diagnosis and patient-physician communication.

Behavioural differences between psychiatric patients with confirmed versus non-confirmed traumatic brain injuries.

The relationship between history of Traumatic Brain Injury (TBI) and BDI-2 depression scores at admission and discharge from the hospital was assessed in acutely hospitalized psychiatric patients. The participants were assigned to three groups: (1) no reported history of TBI (n = 18), (2) reported but not confirmed TBI history (n = 13), and (3) reported and confirmed TBI history (n = 15). It was found that confirmed history of TBI was associated with elevated BDI-2 depression scores. In contrast, the non-confirmed TBI group was characterized by over-reporting of psychological distress, as measured by MMPI-2 validity indices, 100% prevalence of alcohol use history, and depression scores that were intermediate between the control and confirmed TBI groups.

Psychiatric treatment outcome following traumatic brain injury.

The relationship between self-reported history of traumatic brain injury (TBI) and psychiatric treatment outcome was investigated. TBI was hypothesized to be frequent, associated with cognitive deficits on neuropsychological testing, and less amenable to standard psychiatric treatment. Subjects were 42 psychiatric patients with a self-reported history of TBI and 25 psychiatric patients with no TBI history. Subjects received approximately 2 weeks of inpatient psychiatric treatment. Subjects received neuropsychological testing and completed the Brief Symptom Inventory weekly. TBI was frequent (66% of subjects); multiple injuries were common. Neuropsychological performance was generally average in both groups with few group differences. Subjects, on average, reported significantly decreased psychiatric symptoms on discharge. However, the TBI group appeared to improve less than the control group; group status was a significant predictor of treatment outcome. Implications of results for assessment and treatment of psychiatric disorders in patients with a history of TBI are discussed.

K-FAST and WRAT-3: are they really different?

The Kaufman Functional Academic Skills Test (K-FAST) was introduced as an alternative to the Wide Range Achievement Test - Revision 3 (WRAT-3). The goal was to provide a measure that would help determine whether individuals have the adequate reading and mathematical skills to function appropriately in society. Fifty-one individuals from neuropsychologically diverse populations were tested using the K-FAST, WRAT-3, and Kaufman Brief Intelligence Test (K-BIT). Strong correlations were found between the various raw and standard scores of the K-FAST and WRAT-3, indicating that the administration of both tests is redundant; and scores on both tests also correlate well with performance on the K-BIT.

The relationship of daily stress and health-related behaviors to adolescents' cholesterol levels.

It has been well established that some of the major risk factors for coronary heart disease are related to lifestyle, that is, behaviors that are potentially modifiable. Although studies have identified psychosocial stress as a factor associated with elevated cholesterol levels in adults, this relationship has not been thoroughly examined in adolescents. The present study investigated the relationship between daily life events and total cholesterol levels among 104 high school students. The contributions of health-related behaviors, such as dietary patterns, physical activity, smoking, and television viewing, were also examined. Hierarchical multiple regression analyses showed that scores on a scale of daily life events explained a significant portion of the variance in cholesterol measurements. However, when the sample was stratified by gender, this effect remained significant for adolescent females but not males. Overall, females reported a greater degree of negative health behaviors than did males. Implications of these findings are discussed.

Prevalence of traumatic brain injury in psychiatric and non-psychiatric subjects.

Traumatic brain injury (TBI) and its sequelae may impact the expression and treatment of psychiatric disorders. The prevalence of TBI in psychiatric patients is unknown and investigations in the general population are limited. This study examined the prevalence of TBI with loss of consciousness in mental health setting patients (n = 231), general hospital and university staff and students (n = 534) and non-psychiatric medical clinical patients (n = 59). The Traumatic Brain Injury Questionnaire was used to assess TBI. A greater percentage of psychiatric patients reported TBI than medical patients or staff and students. Traumatic brain injuries were typically mild--moderate, medical assistance was frequently sought and use of alcohol and drugs was reported in a minority of TBI incidents. Multiple injuries were most common in psychiatric patients. The percentage of medical patients and staff and students reporting TBI was similar to previous research. The greater percentage of psychiatric patients reporting TBI indicates the need to assess TBI in this population. The role of TBI in the emergence, expression and treatment outcome of psychiatric disorders and the risk factors that leave psychiatric patients vulnerable to TBI should be further examined.

Subacute Pb exposure during development and unbaited tunnel maze performance in mice.

Although research has linked chronic, low-level Pb exposure to behavioral and cognitive changes in humans and animals, far less is known about the effects of transient, subchronic Pb exposure during early postnatal development. The need to understand such effects is underscored by the possibility that subchronic Pb exposure may not produce chronically elevated blood-Pb levels, but may produce long-term behavioral changes. To test this hypothesis, we investigated the effect of low-level Pb exposure on unbaited tunnel maze performance in Binghamton Heterogeneous Stock mice. Mice were either nontreated or given subchronic sodium acetate, 5, 10, or 25 mg/kg Pb acetate intragastrically on postnatal (PN) days 6, 9, 12, 15, and 18. No further Pb exposures were given after postnatal day 18. Blood-Pb measurements were taken from selected mice on PN 18, 19, 23, 28, and 38. On PN 38-42, all mice were individually tested in an unbaited tunnel maze under nondeprived conditions. Locomotor activity, exploration, and experience-dependent changes in cul-de-sac entries were recorded. Although Pb did not affect bodyweight and blood-Pb levels were below 10 microg/dl at the time of behavioral testing, a history of low-level preweaning Pb exposure caused a dose-dependent increase in cul-de-sac entries. This behavioral change was dissociable from changes in bodyweight, degree of exploration or an a priori bias to enter cul-de-sacs. The current results support the hypothesis that brief, subchronic Pb exposure during development produces behavioral changes that last well beyond the exposure period, even when blood Pb declines to within "acceptable" levels (l0 microg/dl).

The malingering of multiple sclerosis and mild traumatic brain injury.

In this investigation, neuropsychological testing was conducted with 69 college students that were instructed to malinger either multiple sclerosis (MS) or traumatic brain injury (TIB) or were non-malingering controls. The two malingering groups were divided into informed and non-informed groups. The informed groups received information concerning their respective condition, and the non-informed groups were asked simply to malinger. Generally, all malingering groups performed considerably below the levels of non-malingering controls on measures of attention, learning and memory, word fluency, abstract reasoning, visuoconstruction and manual dexterity. There appeared to be no difference in the manner in which subjects attempted to malinger MS as opposed to TBI. However, the severity of the portrayed deficit suggested by the test scores was disproportionate to the severity of the injury being requested. The pattern of deficit presented was quite global, with well below average performance demonstrated by all malingering groups across all domains.

Behavioral components of milk-induced activation in neonatal rat pups.

Neonatal rat pups exhibit a complex constellation of behaviors in response to a variety of salient stimuli such as the odor of milk or maternal saliva, stroking with a soft brush, electrical brain stimulation, and intraoral infusions of milk. Although psychobiologists have used the term "behavioral activation" to refer to such behavioral displays, the exact nature of "behavioral activation" and its underlying neural substrates have yet to be elucidated. This study was undertaken to characterize "behavioral activation" quantitatively to describe and define this apparently global pattern of response in terms of possible underlying components. Principal components analysis suggested that "behavioral activation" may be comprised of separable ingestive, exploratory, and locomotor behavioral "assemblies."

Acute and longer term effects of meso-2,3 dimercaptosuccinic acid (DMSA) on the behavior of lead-exposed and control mice.

We investigated the effect of chelating agent meso-2,3 dimercaptosuccinic acid (DMSA) on spatial learning and forced-swim immobility in Binghamton Heterogeneous Stock (HET) mice. Forced-swim immobility (characterized by increasingly frequent bouts of complete motionlessness in a forced-swim test, i.e., behavioral despair) is reduced by exposure to lead. In Experiment 1, male and female HETs (n = 81) were assigned to lead-exposed (0.5% lead acetate ad lib in drinking fluid), pair-fed (PF), or water control groups. Six weeks after the termination of lead exposure, half of each group was injected intraperitoneally (IP) with 50 mg/kg DMSA or vehicle once per day for 5 days. Following treatment, all animals were tested for acquisition and extinction in the Morris Water maze, followed by immobility testing in an inescapable forced-swim task. Neither Pb nor DMSA affected Morris maze performance. However, consistent with previously published work, Pb reduced immobility in the forced-water swim relative to both PF and water controls. Additionally, lead-exposed males, but not females, showed sustained improvement following DMSA treatment on immobility measures. Experiment 2 was designed to demonstrate the effect of the above DMSA protocol on blood-Pb, and also examined the immediate effects of DMSA on immobility during treatment. Thus, in Experiment 2, animals were exposed to an identical Pb and DMSA treatment protocol, but the effects of DMSA on immobility during the course of DMSA treatment were measured, and animals were sacrificed immediately after treatment so that blood-Pb measures could be taken. Under these circumstances, DMSA markedly reversed the lead-induced reduction in immobility immediately during the treatment phase. Although DMSA clearly reduced blood-lead in males, its influence on female blood levels was far less. Taken together, the data from these experiments suggest that DMSA ameliorates lead-induced immobility changes in mice, but that gender may modulate DMSA's effect on blood-lead and longer-term behavioral effects. However, further work is needed to clarify the role of gender in response to DMSA.

The K-BIT: A screen for IQ in six diverse populations.

Performance data were collected on the Kaufman Brief Intelligence Test (K-BIT) from a total of 196 individuals from six diverse populations. College students did best, followed closely by closed head-injured adults and their controls; the order of performance then was learning-disabled children, psychiatric patients, and finally, neurosurgical patients in the acute stages of recovery.

Prevalence of traumatic brain injury in an inpatient psychiatric population.

This study investigated the prevalence of traumatic brain injury (TBI) in an inpatient psychiatric population. We hypothesized increased prevalence of TBI relative to the general population due to a variety of risk factors observed in psychiatric patients. One hundred (mean age = 34) psychiatric inpatients completed the revised Head Injury Questionnaire. Chart review of 17 subjects reporting injuries established whether injuries were documented in medical records. Sixty-eight percent of this psychiatric population reported one or more injuries in which they were unconscious or dazed. This number is higher than the prevalence in the general population. Injuries were generally of mild to moderate severity; multiple injuries were common. Chart review of 17 subjects reporting TBI indicated that histories of TBI had not been noted in the medical record. Finally, 63% of TBI subjects reported that their injury predated the onset of their psychiatric symptoms. These results suggest a possible role of TBI in psychiatric symptomatology and have implications for psychiatric treatment in this population.

Dietary iron and exposure to lead influence susceptibility to seizures.

Previous work in this laboratory showed that concurrent consumption of an iron-deficient diet and exposure to lead caused seizure activity in Albany heterogeneous (HET) stock mice. In the present investigation, 26 Albany HET mice (ages 35 to 57 days of age) ate either an American Institute of Nutrition approved iron-sufficient (30 ppm) diet or an iron-deficient (less than 3 ppm) diet and drank either a 0.5% lead solution or distilled water for 12 weeks. We measured several activities in an open-field, hole-board apparatus, and spontaneous seizures which occurred during testing, changes in body weight, and hemoglobin levels. Replicating previous findings, mice fed the iron-deficient diet and treated with lead had more seizures with longer durations and longer postictal periods than animals given the iron-sufficient diet but also treated with lead. Mice not exposed to lead did not seize. Both lead-treated groups had lower rates of body-weight gain over the 3-mo. period and lower hemoglobin values than nonlead-treated animals. Changes in activity were observed in the open field as a function of diet and exposure to lead.

DMSA chelation during co-exposure to lead: increased locomotor activity in lead-exposed mice but not controls.

We investigated the effect of chelating agent meso-2,3 dimercaptosuccinic acid (DMSA) on indices of "hyperactive" behavior in lead-exposed and control Binghamton Heterogeneous Stock (Het) mice. As expected, 6 weeks of ingestion of 0.5% lead acetate in drinking water reduced immobility in a forced water swim relative to controls. DMSA did not attenuate this behavioral change. In fact, DMSA interacted with lead exposure to increase locomotor activity in the forced water swim. DMSA also apparently excacerbated lead's tendency to reduce immobility. While any generalizations to human populations should be cautioned, these results and others suggest the need for further research.

Performance data for traumatic brain-injured subjects on the Gordon Diagnostic System (GDS) tests of attention.

Thirty adults with traumatic brain injury (TBI) (20 males and 10 females, mean age 40 years) and a non-injured control group (12 males and 13 females, mean age 41 years) were tested on 16 tests of attention including three tasks of the Gordon Diagnostic System (GDS), a relatively new set of attention tasks. No differences between groups were found on age or education. Both groups had estimated IQs in the average range. Performance data for the GDS are presented for the TBI and CON groups. Mild to moderate deficits of attention were seen in the TBI group relative to controls on the Vigilance and Distractibility tasks. No differences between groups were seen on the Standard Delay groups. Person product moment correlations suggested different patterns of relationships between the GDS tasks and other tests of attention for the TBI and CON groups. These results support the utility of the Vigilance and Distractibility tasks for assessment of attention in a mild to moderately injured population.

Cross generation lead ingestion: behavioral and physiological effects in mice.

We examined some developmental and behavioral sequelae of exposing Binghamton Heterogeneous Stock (HET) mice to a 0.5% aqueous lead acetate solution (as the only available fluid source) for either none, one, two, or three generations. Lead exposure, regardless of generation, resulted in decreased body weight and a delay in age of first eye opening relative to controls, but did not delay home nest return latencies. Drinking the lead solution, across two and three successive generations, resulted in a marked and apparently cumulative decrease in pup viability, as well as an increase in dam fatality rates. However, no such cumulative or residual effects were observed on the behavioral activity of those mice who managed to survive. Perhaps a selection effect for lead-tolerant mice occurred in the present study; such an effect could account for the apparent lack of cumulative and residual behavioral effects.

Lead effects on food competition and predatory aggression in Binghamton HET mice.

The ubiquity of lead in our environment, its toxic nature and its potential to alter behavior of humans and animals has stimulated much research. In addition to the well known, but complex, changes in activity and performance of learned tasks following exposure to lead, an increasing body of literature suggests that changes in social behavior also occur. This study examined the impact of ingesting a 0.5% lead acetate solution (as the only available fluid)--a protocol that results in ca. 100 micrograms/dl blood-levels in our Binghamton Heterogenous (HET) mice--on food competition in both male and female HET mice. Effects of this lead exposure on cricket predation by the same HET mice also were observed. Our results from the food competition study (Experiment I) show, compared with water controls, that such exposure to lead increases both food possession time and amount of social contact after food consumption; but very little agonistic behavior took place in either the water control or lead-exposed competition testing sessions. In the cricket predation observations (Experiment II) there was a tendency for lead exposure to reduce the latency of males to attack, and the indication that lead-exposed females initially attacked a cricket's legs more often than any of the other groups. In fact, suggestions of such gender x treatment interactions occurred in both the food competition and the predation work. Overall, we believe our results, in conjunction with other relevant literature, suggest that exposure to lead reduced the individual's general fitness, even when levels are relatively low.

Manual asymmetries during verbal and spatial block design construction.

To examine the effects of cognitive task demands on manual asymmetry, 40 male and 40 female college students were asked to simultaneously construct two replicas of a verbal or spatial block design task, one with each hand. In addition, a verbal and spatial competition task also was performed concurrently with each of the two primary tasks in a dual task paradigm. The spatial primary task elicited increased left-hand use relative to baseline performance, but only in males. An increase in right-hand use was observed during performance of the verbal primary task, again primarily among males. The effects of concurrent cognitive tasks on hand utilization were observed only in subjects performing the verbal primary task, and only when the concurrent task was verbal in nature. Implications for theories of functional cerebral lateralization are discussed.